An automobile is commonly equipped in an interior thereof with a wire harness (internal wiring), via which power supply, signal communication, sensing, etc. to automotive electric components are provided. The wire harness primarily comprises automotive electric wires, protection members, and connectors, and metal wires consisting primarily of copper are generally used for conductors of the automotive electric wires.
In the light of the demand in recent years for improvement in fuel consumption of automobile, weight saving of automotive components is promoted. The demand for weight saving of the wire harness is also unexceptional. In addition, in the light of the need for resources saving and recycle of resources, reduction in quantity of copper used is also demanded.
Two prominent characteristics are required for the electric wire. One is electric conductivity and another is strength of the electric wire. Since copper often used for the conductor of the automotive electric wire is a metal of very low in electrical resistance, even a copper wire having a relatively small wire diameter can provide sufficient conductivity for the electric wire, but it is required to be increased in diameter to a certain extent to keep a required strength for the electric wire. In view of this, the copper wire is required to keep a required strength of the electric wire, while reducing an amount of copper used.
On the other hand, there is proposed a conductor having a copper layer around an outside of the stainless steel wire (Cf. Patent Document 1: JP Laid-open (Unexamined) Patent Publication No. Hei 1-283707, and Patent Document 2: JP Examined Patent Publication No. Hei 7-31939, for example). Additionally, there is proposed a twisted wire formed by twisting together the stainless steel wire and the copper wire (Cf. Patent Document 3: JP Examined Patent Publication No. Sho 63-23015, and Patent Document 4: JP Laid-open (Unexamined) Patent Publication No. Hei 1-225006, for example).
Patent Document 1: JP Laid-open (Unexamined) Patent Publication No. Hei 1-283707,
Patent Document 2: JP Examined Patent Publication No. Hei 7-31939,
Patent Document 3: JP Examined Patent Publication No. Sho 63-23015, and
Patent Document 4: JP Laid-open (Unexamined) Patent Publication No. Hei 1-225006.